The present disclosure relates to a device and method for inserting at least one insertion member having a puncturing tip into body tissue a patient and for fixing it to the skin of the body. The present disclosure also relates to a device and method for inserting a soft member into the body tissue.
For patients with a regular requirement for a medication administered by direct delivery into the body tissue or into the blood stream, for example, patients suffering from pain or patients with type I or type II diabetes, it can be useful to supply the body with the required quantity of medication in liquid form via a cannula that is introduced at a suitable location into the body and that remains there over a period of time. For this purpose, a cannula arrangement, designated as an infusion set or port, depending on its design, is secured on the patient's skin in such a way that the cannula passes through the skin and into the body.
Efforts are also increasingly being made to monitor certain medical parameters of a patient, for example, the blood sugar value, continuously over a long period of time. For this purpose, a sensor arrangement, for example, is placed on the patient's body and, with a puncturing tip, a suitable sensor passes through the skin and into the patient's body.
To avoid infections, the infusion set, the port or the sensor arrangement should be changed at regular intervals, for example, every three days. In outpatient treatment, for example in the case of diabetics, this is often done by the patients themselves and, on account of the introduction of the infusion cannula or the puncturing tip, respectively, into the skin, is associated with a certain amount of pain. It is therefore important that such infusion sets, ports or sensor arrangements can be applied easily and safely, which may be why many manufacturers have started designing their products as insertion heads for special insertion devices with the aid of which these insertion heads can be applied to the patient's body.
Also, in order to keep irritation of the application site during the application period at a minimum, it is desirable that the cannula or sensor which is inserted into the body be soft, i.e. is designed as an element which can have certain flexibility so that it can follow certain movements of the body tissue. However, due to this structural flexibility, such cannulas and sensors require for their introduction into the body a guiding element which provides a puncturing tip and stiffens them during the introduction movement. Furthermore, after the introduction of the cannula or sensor into the body, the guiding element must be removed and disposed off in a safe manner since it is contaminated and contact with other persons could result in the transfer of diseases such as, in case of an accidental piercing of the skin of the person with the contaminated puncturing tip of the guiding element.
Some known insertion devices for applying infusion sets have a base plate attached by skin compatible glue to a patient's body. With these insertion devices, the infusion sets can be placed onto the application site of the body by the force of a pre-tensioned spring, so that the cannula of the infusion set abruptly penetrates into the body tissue and the infusion set with its base plate is affixed to the skin. Even though with these known insertion devices, the application of infusion sets can be made easier and due to the quick and targeted puncturing procedure, the pain associated with the application can be significantly reduced compared with a manual application, there is still a potential for further improvement. A further disadvantage of these devices is that the fixation of the infusion set to the skin often is unsatisfactory so that, after the application, the infusion set must be pressed by hand against the skin in order to ensure a proper affixation. This, however, can be associated with the risk that the cannula might be flexed or be partially pulled out of the tissue resulting in irritation of the application site.
Other known insertion devices for infusion sets with soft cannulas are stiffened by a guiding needle, by which the infusion set can be placed onto the application site by the force of a pre-tensioned spring so that the guiding needle with the cannula abruptly penetrates into the tissue. After application of the infusion set, the insertion device and the guiding needle are removed from the infusion set, either together or separately. In the case where the insertion head is applied by hand, after the application, the guiding needle is removed by gripping a holder connected to it and by pulling this holder in the opposite direction of the inserting direction of the cannula, thereby removing the guiding needle from the soft cannula. After the guiding needle is pulled out of the cannula, it is pivoted in a protected position within a housing forming the holder. In the case where the insertion head is applied with an insertion device, after the application either in a first step the insertion device is removed from the application site and after that in a second step the guiding needle is removed in the way described before or, in case a specific insertion device is used for applying the insertion head, in a first step the insertion device is removed together with the guiding needle and in a second step the guiding needle is released from the insertion device and after that is pivoted into a protected position within the housing forming the holder. While with the disclosed insertion devices the introduction of the soft cannula of the infusion set into the tissue of the body is considerable easy and safe, the removal of the guiding needle needs a certain sleight of hand and may cause irritation at the puncture site by forces exerted onto the inserted cannula if not performed properly. Furthermore, the removal of the guiding needle is associated with a certain risk of injury, since after its removal from the infusion set it is uncovered and must be handled with care. An application by hand in any case has the disadvantage that it needs certain skills and, since it is accompanied by a certain pain, costs the patient quite an effort.
Therefore, there is a need for a device where the application of an infusion set with a soft cannula becomes easy and safe even for unskilled persons. The insertion can take place at a higher speed compared to known devices, resulting in a reduction of the pain and a reduction in the risk of an irritation of the puncture site. In addition, the risk of an unintended contact with the contaminated guiding needle is substantially eliminated.